The answer to your question is -10
Answer: x= ±(√30) / 5
Step by step:
Answer:
x = 53
y = 30
Step-by-step explanation:
Step(I):-
Given equations are
x -2y =-7 ...(I)
5x-9y =-5 ..(ii)
The matrix form AX = B
![\left[\begin{array}{ccc}1&-2\\ 5 & -9\\\end{array}\right] \left[\begin{array}{ccc}x\\y\\\end{array}\right] = \left[\begin{array}{ccc}-7\\-5\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26-2%5C%5C%205%20%20%26%20-9%5C%5C%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5C%5C%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-7%5C%5C-5%5C%5C%5Cend%7Barray%7D%5Cright%5D)
The determinant
By using Cramer's Rule
Δ₁ = ![\left[\begin{array}{ccc}-7&-2\\\\-5&-9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-7%26-2%5C%5C%5C%5C-5%26-9%5Cend%7Barray%7D%5Cright%5D)
The determinant is Δ₁ = -9 X -7 - (10 ) = 53
x = Δ₁ / Δ
x = 53
The determinant
Δ₂ =
Δ₂ = -5 +35
y = Δ₂/Δ = 30
<span>In a normal distribution 68.27% of the values are within one standard deviation from the mean, 95.5% of the values are within two standard deviations from the mean, and 99.7 % of the values are within three standard deviations of the mean
With that you have the answer to the three questions:
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<span>a. significantly high (or at least 2 standard deviations above the mean).
99.5% of the values are within 2 standard deviations from the mean, half of 100% - 95.5% = 4.5% / 2 = 2.25% are above the mean, so the answer is 2.25%
b. significantly low (or at least 2 standard deviations below the mean).
The other half are below 2 standard deviations, so the answer is 2.25%
c. not significant (or less than 2 standard deviations away from the mean).
As said, 95.5% are within the band of two standard deviations from the mean, so the answer is 95.5%.
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